Researchers think it's the effect of convection currents in our planet's molten interior that causes the entire Earth to behave as one gigantic magnet, with a North and South Pole.
研究者们认为，是地球内部熔岩里对流流的作用使得整个地球像个拥有南北磁极的巨型磁体一样运转。
2
Remove the foreign forces, because the magnetic pole mutually exclusive, magnetic magnet will return to the status of the lowest magnetic energy.
去掉外力后，由于磁系统的磁极相互排斥，磁力将使磁体恢复到磁能最低的状态。
3
Bonded multi-polemagnet rotors are used in a wide variety of speed and commutation applications such as to rotary encoders, speedometers and machine controls.